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Download features from an OGC API Features service

Source: R/get_feature_ogc.R
get_feature_ogc.Rd

get_feature_ogc() provides a modern alternative to get_feature_wfs(). It retrieves vector data from an OGC API Features service. See https://ogcapi.ogc.org.

Usage

get_feature_ogc(
  url,
  collection,
  bbox = NULL,
  datetime = NULL,
  properties = NULL,
  cql_filter = NULL,
  limit = NULL,
  crs = NULL,
  quiet = TRUE,
  ...
)

Arguments

url

A character string with the base URL of the OGC API (the landing page).

collection

A character string with the ID of the collection (layer).

bbox

A bounding box to filter features. Can be a numeric vector of length 4 (c(xmin, ymin, xmax, ymax)) or an object of class bbox (from sf::st_bbox()). Note: OGC APIs generally expect the bbox coordinates to be in WGS84 (EPSG:4326).

datetime

A character string representing a time instant or time interval (e.g., "2018-02-12T23:20:50Z" or "2018-02-12T00:00:00Z/2018-03-18T12:31:12Z").

properties

A character vector of specific column names to return.

cql_filter

A character string containing a CQL2-text filter to apply attribute or complex spatial filtering on the server. See Common Query Language filter specifications.

limit

Numeric. Maximum number of features to retrieve. If NULL (default), all available features will be fetched via automatic API pagination.

crs

Target Coordinate Reference System (CRS) as an EPSG code or CRS object. If provided, the output will be automatically transformed to this CRS.

quiet

Logical. Should the download progress be suppressed? Defaults to TRUE.

...

Additional name-value pairs passed on to httr2::req_url_query.

Value

An sf (simple feature) object.

See also

Other topics on using web services: add_wms_be_cartoweb(), add_wmts_nl_brt(), check_ogc_collection(), get_coverage_wcs(), get_feature_wfs(), get_wcs_layers()

Examples

if (FALSE) { # \dontrun{
# Base URL for the Digitaal Vlaanderen Wegenregister (Road Register)
api_url <- "https://geo.api.vlaanderen.be/Wegenregister/ogc/features/v1"

# 1. Basic usage: Fetch 10 road segments
roads_sample <- get_feature_ogc(
  url = api_url,
  collection = "Wegsegment",
  limit = 10
)

# 2. Spatial Filtering & CRS Transformation:
# Fetch features within a WGS84 bounding box and project to Belgian Lambert72
my_bbox <- sf::st_bbox(
  c(xmin = 4.39, ymin = 51.21, xmax = 4.40, ymax = 51.22),
  crs = sf::st_crs(4326)
)
roads_bbox <- get_feature_ogc(
  url = api_url,
  collection = "Wegsegment",
  bbox = my_bbox,
  crs = 31370
)

# Base URL for Historical Land Use (Ferraris map)
hist_url <- "https://geo.api.vlaanderen.be/HistLandgebruik/ogc/features/v1"

# 3. Attribute Selection:
# Fetch only specific columns
ferraris_lite <- get_feature_ogc(
  url = hist_url,
  collection = "Lgbrk1778",
  limit = 100,
  properties = c("KLASSE")
)

# 4. Advanced CQL2 Attribute Filtering:
# Filter features directly on the server
roads_filtered <- get_feature_ogc(
  url = api_url,
  collection = "Wegsegment",
  limit = 50,
  cql_filter = "morfologischeWegklasse = 'dienstweg'"
)
} # }